I've been a music producer for years myself, you put good efforts in but you have to realize it doesn't have to be applicable for every 'music maker'. Even the once considered 'best' DJ Tiesto isn't able to read one note of a sheet. You didn't even mention MIDI once as that goes to show how little you know.
(Although knowledge doesn't always equate good music, your talents and feelings will do most work no matter how little 'music theory' you know (contrary to popular belief)).
If you are really interested in making music, do your own research every day and don't rely on little tutorials like these.
Here are some basic terms which you'll come across:
-DAW (Digital Audio Workstation, basically your main software in which you can sequence your music. Be it with recorded audio/samples, or MIDI (Digital Instruments))
-VST (A smaller bit of software which can act as a plugin IN-to your DAW to act as an instrument, offering parameters to design your own unique synthetic sound. You can edit the MIDI which governs the notes played by either clicking on a keyroll in your DAW, or buying a MIDI keyboard.
-MIDI (THE technology for today's music. Most of what you hear on the music is digitally produced rather than being raw-ly recorded. MIDI is basically allowing you to record notes, including length and velocity. Which then gets sent to your VST to produce the actual sound)
-Audio Interface (Basically an external sound card, most internal sound cards in PCs are not built to handle all the processes done in your DAW, and audio interfaces will often have a jack plug(for guitars), and condensor microphone XLR plugs including phantom power (necessary to have, for quality recording).
It helps to use google. If you want to learn individual instruments, it's not necessary to know music theory. Just listen to other pieces of music and how it's played. You can either purchase the actual instrument(lol) to record in your microphone, or emulate them with a VST using your MIDI keyboard (decent ones are really cheap nowadays).
You're welcome and don't be overwhelmed by misguided individuals trying to teach you something which doesn't have to be relevant.